1. Radiation – E emitted from a surface
Conduction – kinetic E trans. By contact
Convection – moving air/liquid (boundary)
Evaporation – exchange of latent E
Adaptations to the Physical Environment
 II. Light
III. Heat Exchange
A. Pathways of Exchange

2. Adaptations to the Physical Environment II. Light III. Heat Exchange
Pathways of Exchange
Effects on Organisms
1. Heat Budget
An organisms heat budget is strongly tied to both metabolism (producing heat) and water balance

3. Adaptations to the Physical Environment II. Light III. Heat Exchange
Pathways of Exchange
Effects on Organisms
1. Heat Budget
2. Body Size and SA/V ratio

4. Adaptations to the Physical Environment II. Light III. Heat Exchange
Pathways of Exchange
Effects on Organisms
1. Heat Budget
2. Body Size and SA/V Ratio
3. Effects of Temperature
Increase metabolism, increase production of metabolic waste
Increase evaporation
Increase water demand

5. Adaptations to the Physical Environment
 II. Light
III. Heat Exchange
Pathways of Exchange
Effects on Organisms
Adaptations
Concept of flux:
The rate of exchange of energy or matter (water) is a function of:
- SA/V
- energy/matter concentration gradient
- characteristics of the surface (covered by oils or hairs?)
Cushion plants
Cacti

6. White-tailed Deer - Bergmann’s Rule (1847) Bears
Adaptations to the Physical Environment
 II. Light
III. Heat Exchange
Pathways of Exchange
Effects on Organisms
Adaptations
1. Structural
White-tailed Deer
- Bergmann’s Rule (1847)
Bears
Larger (smaller SA/V ratio) as latitude increases

7. Bergmann’s Rule (1847) Allen’s Rule (1849)
Adaptations to the Physical Environment
 II. Light
III. Heat Exchange
Pathways of Exchange
Effects on Organisms
Adaptations
1. Structural
Bergmann’s Rule (1847)
Allen’s Rule (1849)
Lower SA/V – ‘rounder’ and latitude increases

8. Humans: Adaptations to the Physical Environment II. Light
III. Heat Exchange
Pathways of Exchange
Effects on Organisms
Adaptations
1. Structural
Humans:
PETER T. KATZMARZYK AND WILLIAM R. LEONARD. (1998) Climatic Influences on Human Body Size and Proportions: Ecological Adaptations and Secular Trends. AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY 106:483–503.
Bergmann

9. Humans: Adaptations to the Physical Environment II. Light
III. Heat Exchange
Pathways of Exchange
Effects on Organisms
Adaptations
1. Structural
Humans:
PETER T. KATZMARZYK AND WILLIAM R. LEONARD. (1998) Climatic Influences on Human Body Size and Proportions: Ecological Adaptations and Secular Trends. AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY 106:483–503.
Allen

10. increase edge/SA ratios, and increase SA/V ratios - maximize the loss of absorbed heat energy
shade leaf - broad
sun leaf - deeply cut; narrow

11. Adaptations to the Physical Environment II. Light III. Heat Exchange
Pathways of Exchange
Effects on Organisms
Adaptations
1. Structural
Hairs, spines, feathers…
create boundary layer.

12. Adaptations to the Physical Environment II. Light III. Heat Exchange
Pathways of Exchange
Effects on Organisms
Adaptations
1. Structural
2. Physiological
Homeotherms Poikilotherms
Constant temp Variable temps
Mostly birds and mammals; some large fish (tuna)
Hummingbirds, some mammals that go into torpor regularly
Endothermy: Generate heat
Ectothermy: Temperature is environmentally determined
Some tropical species, deep sea species, some dinosaurs (‘gigantotherms’)
Most fish, inverts, amphibians, reptiles

13. Adaptations to the Physical Environment II. Light III. Heat Exchange
Pathways of Exchange
Effects on Organisms
Adaptations
1. Structural
2. Physiological
Increase surface blood flow to dissipate heat

14. Adaptations to the Physical Environment II. Light III. Heat Exchange
Pathways of Exchange
Effects on Organisms
Adaptations
1. Structural
2. Physiological
Decrease metabolism to reduce gradient and rate of heat loss

15. Adaptations to the Physical Environment II. Light III. Heat Exchange
Pathways of Exchange
Effects on Organisms
Adaptations
1. Structural
2. Physiological
Counter-current exchange to maximize heat retention

16. Adaptations to the Physical Environment II. Light III. Heat Exchange
Pathways of Exchange
Effects on Organisms
Adaptations
1. Structural
2. Physiological
3. Behavioral
Bask

17. Adaptations to the Physical Environment II. Light III. Heat Exchange
Pathways of Exchange
Effects on Organisms
Adaptations
1. Structural
2. Physiological
3. Behavioral
migrate